61143780 has 96 divisors (see below), whose sum is σ = 179601408. Its totient is φ = 15523200.

The previous prime is 61143779. The next prime is 61143839. The reversal of 61143780 is 8734116.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 131829 + ... + 132291.

It is an arithmetic number, because the mean of its divisors is an integer number (1870848).

Almost surely, 2^61143780 is an apocalyptic number.

61143780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61143780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89800704).

61143780 is an abundant number, since it is smaller than the sum of its proper divisors (118457628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61143780 is a wasteful number, since it uses less digits than its factorization.

61143780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577 (or 575 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 61143780 is about 7819.4488296810. The cubic root of 61143780 is about 393.9587595441.

Adding to 61143780 its reverse (8734116), we get a palindrome (69877896).

The spelling of 61143780 in words is "sixty-one million, one hundred forty-three thousand, seven hundred eighty".